USP21 negative regulates RLR pathway by stabilizing EV-A71 2A pro to promote EV-A71 replication
10.3760/cma.j.cn112866-20240226-00027
- VernacularTitle:USP21增强EV-A71 2A pro稳定性负向调控RLR信号通路促进EV-A71复制
- Author:
Xinyu YANG
1
;
Mengyuan TANG
;
Zhiping CHE
;
Yan CHEN
;
Yang PENG
;
Jinhong MA
;
Weifeng SHI
;
Wei ZHOU
Author Information
1. 苏州大学附属第三医院（常州市第一人民医院）医学检验科，常州 213003
- Publication Type:Journal Article
- Keywords:
Enterovirus group A type 71;
Ubiquitin specific protease 21 (USP21);
2A protease (2A pro);
RIG-I-like receptor (RLR) signaling pathway
- From:
Chinese Journal of Experimental and Clinical Virology
2025;39(1):18-26
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the role of ubiquitin-specific protease 21 (USP21) in enterovirus group A type 71 (EV-A71) infection.Methods:Peripheral blood mononuclear cells (PBMC) were obtained from a cohort of 24 children infected with EV-A71 and 24 healthy children. Expression of USP21 was determined by real-time fluorescence quantitative PCR (qPCR). Additionally, the impact of USP21 overexpression or knockout on EV-A71 replication was evaluated using a combination of qPCR and western blot (WB) analysis. Furthermore, WB was employed to measure the levels of EV-A71 structural protein VP1, phosphorylated interferon regulatory factor 3 (IRF3) and other key molecules in the RIG-I-like receptor (RLR) signaling pathway. Co-immunoprecipitation (Co-IP) was utilized to investigate the effects of USP21 on the ubiquitin levels of EV-A71 nonstructural protein 2A protease (2A pro). Results:In comparison to healthy children, the expression of USP21 mRNA in PBMC of children infected with EV-A71 was notably elevated. The overexpression of USP21 significantly enhanced the cytopathic effects induced by EV-A71, upregulated levels of VP1 mRNA and protein, and facilitated EV-A71 replication, leading to a decrease in cell activity with increasing levels of USP21 transfection. Following the knockout of the USP21 gene, the VP1 mRNA levels were significantly declined in comparison to the control group. Furthermore, the overexpression of USP21 was found to have no impact on the transcriptional activity of EV-A71 2A pro. However, it was observed to enhance the expression of 2A pro protein, reduce the ubiquitination of 2A pro, suppress the protein levels of mitochondrial antiviral signaling protein (MAVS) and melanoma differentiation-associated gene 5 (MDA5), as well as decrease the phosphorylation of IRF3. Additionally, the induction of IFN-β mRNA by EV-A71 infection was downregulated. Conclusions:USP21 has been shown to enhance the replication of EV-A71 through the downregulation of 2A pro ubiquitination, suppression of MAVS and MDA5 protein expression, and inhibition of the interferon signaling pathway.
